Merging in latest from upstream (HDFFV/hdf5:refs/heads/develop)

* commit 'a8892bb42d6f6e4fbc30fae0eb2b957f81c938b9': (45 commits)
  Oops, remove more C99 designated initializers for VS 2010 compatibility.
  Add an #include to get a function declaration.
  Don't use C99 designated initializers, they're not compatible with Visual Studio 2010.
  Quiet some more maybe-uninitialized warnings---each is a false positive, *sigh*.  This is more code that may not compile with VS2010, *sigh sigh*.
  Always warn on maybe-uninitialized.  -Wincompatible-pointer-types was not available until GCC 5, so enable it only if that's the GCC version we're using.
  Only promote maybe-uninitialized warnings to errors on GCC 8.  Even on GCC 8, there may be false positives at low optimization levels?  I need to check.
  Only use -Werror=cast-function-type with GCC 8 and later.
  Put all of the -W options back into the order I found them in so that it's easier to compare old and new config/gnu-flags.
  Add new source files to CMakeLists.txt.
  Mention the -Werror= flags in libhdf5.settings.in.
  free -> HDfree
  Promote decleration-after-statement warnings to errors.
  Quiet decleration-after-statement warnings.
  Move a statement under some declarations since some vintages of Visual Studio don't like declarations after statements.
  Document H5D__chunk_mem_xfree_wrapper().
  Undo accidental test deletion.
  Oops, delete a debug printf that snuck in here.
  Undo my changes to the HD macros, hadn't really intended those to be on this branch....
  Make errors of some more warnings.  Move disabled warnings to DEVELOPER_WARNING_CFLAGS.  Put just one warning option on a line, and sort some of the options.
  Cast to the parameter type, H5VL_token_t *, instead of to unsigned char *.
  ...

2 files changed, 88 insertions, 12 deletions

diff --git a/config/commence.am b/config/commence.am
index a16eee5..830c494 100644
--- a/config/commence.am
+++ b/config/commence.am
@@ -70,7 +70,7 @@ H5CPP=${DESTDIR}$(bindir)/h5c++
 # instead of CFLAGS, as CFLAGS is reserved solely for the user to define.
 # This applies to FCFLAGS, CXXFLAGS, CPPFLAGS, and LDFLAGS as well.
 
-AM_CFLAGS=@AM_CFLAGS@ @H5_CFLAGS@
+AM_CFLAGS=@AM_CFLAGS@ @H5_CFLAGS@ @H5_ECFLAGS@
 AM_FCFLAGS=@AM_FCFLAGS@ @H5_FCFLAGS@
 AM_CXXFLAGS=@AM_CXXFLAGS@ @H5_CXXFLAGS@
 AM_CPPFLAGS=@AM_CPPFLAGS@ @H5_CPPFLAGS@
diff --git a/config/gnu-flags b/config/gnu-flags
index 6355ccf..bc120a8 100644
--- a/config/gnu-flags
+++ b/config/gnu-flags
@@ -168,12 +168,44 @@ if test "X-gcc" = "X-$cc_vendor"; then
     # NOTE: Disable the -Wformat-nonliteral from -Wformat=2 here and re-add
     # it to the developer flags.
     #
-    H5_CFLAGS="$H5_CFLAGS -pedantic -Wall -Wextra -Wbad-function-cast -Wc++-compat -Wcast-align"
-    H5_CFLAGS="$H5_CFLAGS -Wcast-qual -Wconversion -Wdeclaration-after-statement -Wdisabled-optimization -Wfloat-equal"
-    H5_CFLAGS="$H5_CFLAGS -Wformat=2 -Wno-format-nonliteral -Winit-self -Winvalid-pch -Wmissing-declarations -Wmissing-include-dirs"
-    H5_CFLAGS="$H5_CFLAGS -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wpacked"
-    H5_CFLAGS="$H5_CFLAGS -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-enum -Wswitch-default"
-    H5_CFLAGS="$H5_CFLAGS -Wundef -Wunused-macros -Wunsafe-loop-optimizations -Wwrite-strings"
+    H5_CFLAGS="$H5_CFLAGS -pedantic -Wall -Wextra"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=bad-function-cast"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=cast-align"
+    H5_CFLAGS="$H5_CFLAGS -Wcast-qual -Wconversion"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=declaration-after-statement"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wdisabled-optimization"
+    H5_CFLAGS="$H5_CFLAGS -Wfloat-equal"
+    H5_CFLAGS="$H5_CFLAGS -Wformat=2 -Wno-format-nonliteral -Winit-self -Winvalid-pch"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=missing-declarations"
+    H5_CFLAGS="$H5_CFLAGS -Wmissing-include-dirs"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=missing-prototypes"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=nested-externs"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=old-style-definition"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=packed"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=redundant-decls"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=shadow"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=strict-prototypes"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wswitch-default"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wswitch-enum"
+    H5_CFLAGS="$H5_CFLAGS -Wundef"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wunused-macros"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wunsafe-loop-optimizations"
+    H5_CFLAGS="$H5_CFLAGS -Wwrite-strings"
+
+    #
+    # HDF5 code should not trigger the following warnings under any
+    # circumstances, so ask the compiler to treat them as errors:
+    #
+#   H5_ECFLAGS="$H5_ECFLAGS -Werror=discarded-qualifiers"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=implicit-function-declaration"
+    H5_CFLAGS="$H5_CFLAGS -Wmaybe-uninitialized"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=pointer-sign"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=pointer-to-int-cast"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=switch"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=unused-but-set-variable"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=unused-function"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=unused-parameter"
+    H5_ECFLAGS="$H5_ECFLAGS -Werror=unused-variable"
 
     ######################
     # Developer warnings #
@@ -222,17 +254,34 @@ if test "X-gcc" = "X-$cc_vendor"; then
 
     # gcc 4.3                                                                    
     if test $cc_vers_major -ge 5 -o $cc_vers_major -eq 4 -a $cc_vers_minor -ge 3; then
-        H5_CFLAGS="$H5_CFLAGS -Wlogical-op -Wlarger-than=2560"                   
+        H5_CFLAGS="$H5_CFLAGS -Wlogical-op"
+        #
+        # Lots of noise, questionable benefit:
+        #
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wlarger-than=2560"
+        #
     fi 
 
     # gcc 4.4
     if test $cc_vers_major -ge 5 -o $cc_vers_major -eq 4 -a $cc_vers_minor -ge 4; then
-        H5_CFLAGS="$H5_CFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"
+        H5_CFLAGS="$H5_CFLAGS -Wsync-nand -Wpacked-bitfield-compat"
+        #
+        # Lots of noise, questionable benefit:
+        #
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wframe-larger-than=16384"
+        #
     fi
 
     # gcc 4.5
     if test $cc_vers_major -ge 5 -o $cc_vers_major -eq 4 -a $cc_vers_minor -ge 5; then
-        H5_CFLAGS="$H5_CFLAGS -Wstrict-overflow=5 -Wjump-misses-init -Wunsuffixed-float-constants"
+        H5_CFLAGS="$H5_CFLAGS -Wstrict-overflow=5 -Wunsuffixed-float-constants"
+        #
+        # -Wjump-misses-init makes lots of noise for a questionable benefit.
+        # Can jumping over an initialization in C cause any harm, if
+        # the variable is never *used* before it has been initialized?
+        #
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wjump-misses-init"
+        #
     fi
 
     # gcc 4.6
@@ -244,7 +293,17 @@ if test "X-gcc" = "X-$cc_vendor"; then
 
     # gcc 4.7
     if test $cc_vers_major -ge 5 -o $cc_vers_major -eq 4 -a $cc_vers_minor -ge 7; then
-        H5_CFLAGS="$H5_CFLAGS -Wstack-usage=8192 -Wvector-operation-performance"
+        #
+        # It's not clear that -Wvector-operation-performance warnings are
+        # actionable.
+        #
+        # -Wstack-usage=8192 warnings need better justification;
+        # if justifiable, should be enabled on a branch and swept up there
+        # before burdening the whole development team.
+        #
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wstack-usage=8192"
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wvector-operation-performance"
+
         DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"
         NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=pure -Wno-suggest-attribute=noreturn"
     fi
@@ -263,11 +322,21 @@ if test "X-gcc" = "X-$cc_vendor"; then
     # gcc 5
     if test $cc_vers_major -ge 5; then
         H5_CFLAGS="$H5_CFLAGS -Warray-bounds=2 -Wc99-c11-compat"
+        H5_ECFLAGS="$H5_ECFLAGS -Werror=incompatible-pointer-types"
     fi
 
     # gcc 6
     if test $cc_vers_major -ge 6; then
-        H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized"
+        H5_CFLAGS="$H5_CFLAGS -Wunused-const-variable -Whsa -Wnormalized"
+        #
+        # Unacceptably noisy on HDF5 right now.
+        #
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wnull-dereference"
+        #
+        # Careful!  -Wduplicated-cond, combined with HDF5's heavy use of
+        # macros, can make a lot of noise.
+        #
+        DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wduplicated-cond"
     fi
 
     # gcc 7
@@ -278,6 +347,13 @@ if test "X-gcc" = "X-$cc_vendor"; then
 
     # gcc 8
     if test $cc_vers_major -ge 8; then
+        # For GCC 8, promote maybe-initialized warnings to an error.  GCC 8
+        # reports 0 maybe-uninitialized warnings where earlier versions
+        # make many false reports.  GCC 8 seems to analyze calls to static
+        # in order to detect initializations that occur there.  It's possible
+        # that GCC 8 only performs that analysis at -O3, though.
+        H5_ECFLAGS="$H5_ECFLAGS -Werror=maybe-uninitialized"
+        H5_ECFLAGS="$H5_ECFLAGS -Werror=cast-function-type"
         DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wstringop-overflow=4 -Wsuggest-attribute=cold -Wsuggest-attribute=malloc"
         NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=cold -Wno-suggest-attribute=malloc"
         H5_CFLAGS="$H5_CFLAGS -Wattribute-alias -Wcast-align=strict -Wshift-overflow=2"